Although a variety of treatment devices and/or methodologies have been developed, urinary incontinence for both men and women remains a persistent problem. Heretofore known approaches to the problem are generally recognized as either remedial or corrective. Remedial approaches (i.e., those primarily dealing with the effects of incontinence) have primarily included the use of catheters in combination with collection bags or the like. As circumstances warrant, the wearing of special fluid retaining pants has been an option, all be it an undesirable one, for both social and practical reasons.
Remedial approaches are almost always less attractive than corrective approaches, which generally require the placement or implantation of an indwelling device within the urethra. In general terms, it is the goal of such devices to provide a valving system for a patient's bladder, which system is placed directly in the urethra, and adjacent the bladder. The valving system is ideally activated by the patient upon sensing an urge to urinate, such urge being generally generated at about 20 centimeters of water pressure (20 cm H2O), and deactivated when the bladder has been sufficiently emptied.
Some of the problems and disadvantages of known devices include the deleterious effects (i.e., pitting, depositions, etc.) associated with the urethral environment upon critical device components (e.g., valve actuators, flow conduits, etc.) which at a minimum render such devices less effective, and which at a maximum, cause device component failure or render the device wholly ineffective, which necessitates emergent removal and, as the case may be, urinary tract damage repair. Problems of device leakage, or less than complete emptying of the bladder are also widely known. Furthermore, issues surrounding device (deployment and fit, positioning, repositioning, and retention (i.e., sufficient anchoring) have also been well documented.
Device features are primarily dictated by the anatomical and physiological environment into which they are to be placed. In light of know devices and methodologies, it has become better appreciated that there are several essential requirements which must be met for an indwelling urinary flow control device so as to be effective.
First, the flow control device must not completely occlude urethral passage when intra-bladder pressures are excessive for an extended period of time. It is a widely held view among clinical urologists that on occasions when the bladder is pressurized to beyond approximately 40 cm H2O for more than about 2 hours, an individual is in danger of permanent injury to the kidneys. For this reason, it is desirable for a flow control device to allow passage of at least as much urine, volumetrically, as is being produced by the kidneys once the bladder pressure has reached a threshold value (i.e., approximately 40 cm H2O).
Second, physical straining due to lifting, laughing, coughing, and other “exertions” may produce inter-abdominal forces on the bladder, which may translate to pressures in excess of 40 cm H2O for a short time interval or duration. Such inadvertent stresses must not cause appreciable leakage, even though they may momentarily exceed approximately 40 cm H2O for short durations. Such pressure surges are a natural event, which may be frequently encountered.
Third, the flow control device must allow for remote or natural initiation without physically touching or otherwise contacting the flow control device in order to provide the most protection against introduction of bacteria, which would be likely to contribute to urinary tract infections (UTIs). It is further advantageous that the initiation be painless, sterile, non-invasive, repeatable, not dependent upon hardware that is expensive, cumbersome, difficult to operate or objectionable.
Fourth, the flow control device must be stable with respect to position (i.e., a physiologically properly deployed and stable position), and comfortable to wear, as the urinary tract is sensitive to contact. Inter-urethral stents have been utilized within the male urethra within the prostatic region with many users foregoing such devices for alternate therapies due to feelings of discomfort and/or pain. Many flow control devices have similarly been evaluated for urinary incontinence for females. Based upon clinical findings, many have been shown to be uncomfortable, thus severely retarding their utility as a therapy. Other devices have migrated into the bladder, or have been expelled under straining conditions.
Fifth, flow control devices must have longevity of operation. Working components that are exposed to urine are susceptible to encrustation, which may compromise device operation and thereby place a wearer at risk of injury or even death. Intraurethral flow control devices must not quickly lose functional operation due to either mechanical failure, or blockage of flow passages. This is exceedingly important for a male due to the more difficult, and more inconvenient, removal associated with typical flow control devices.